Plastic bags are in widespread use in a varied and diverse number of household and commercial applications, especially in the food packaging industry. One advantage of plastic bags is their ease of opening and resealing. Some of these bags are reclosable via the use of a reclosable feature such as a reclosable fastener. In many bags, the fasteners can be opened and closed either by pressure or by the use of an auxiliary slider mechanism.
Various arrangements have been utilized heretofore to maintain auxiliary slider mechanisms on fasteners. One arrangement which has been used to prevent or inhibit the slider mechanism from going past the ends of the fastener and coming off of the bag is to incorporate opposing end termination clips at the ends of the fastener. The use of end termination clips, however, increases the cost of producing the bag as it requires an additional component on the bag and an additional piece of equipment in order to place the end termination clips on the bag. In addition, the placement of end termination clips on the ends of the fastener involves an additional processing step which may not be desirable when manufacturing speeds are important.
To avoid using end termination clips to prevent or inhibit the auxiliary slider mechanism from going past ends of the fastener, an alternative arrangement has been employed which involves shaping material from the fastener into opposing end stops or end stop structures which protrude from the fastener or zipper and engage the slider mechanism to prevent or inhibit it from going past the respective ends of the fastener. One method which has been used to shape end stop structures in this fashion has been to ultrasonically smash the opposite ends of the male and female profiles of the fastener to form the protruding end stop structures.
While such protruding end stop structures are effective in preventing the slider mechanism from going past the respective ends of the fastener, many of the materials which have been previously used in forming such protruding end stop structures lack sufficient mechanical strength to hold the slider mechanism on the bag when stresses are applied to the bag during normal bag use. Also, many of the materials which have been previously used in forming such protruding end stop structures require longer welding times and, consequently, slower cycle processing times.
Accordingly, there exists a need for a plastic bag having a slider-operated fastener with protruding end stop structures which may be formed by shaping material from the fastener via shorter weld times and, consequently, shorter processing times. There also exists a need for a plastic bag having a slider-operated fastener with protruding end stop structures which may be formed by shaping material from the fastener and which provide improved strength properties to hold the slider mechanism on the bag. There further exists a need for methods of producing such end stop structures.